vb.net中的Math.Round无法按预期工作

Question

I have this number : 666872700 i need to round it to be : 666900000

I used : Math.Round(666872700,4) but this is not working Is there any easy way in vb.net I can use other than dividing by 100000 then rounding then multiplying by 100000 ?

Answer 1

The documentation for Math.Round clearly states:

Rounds a double-precision floating-point value to a specified number of fractional digits .

So it rounds stuff behind the decimal separator, but not integral part. I know of no other way than dividing, rounding and then multiplying again.

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If you know a little C#, you can use the following extension method Jason Larke wrote in his answer to this question . I don't know whether it works, but you should be able to translate it to VB.NET and try it:

public static class MathExtensions
{
    public static int Round(this int i, int nearest)
    {
        if (nearest <= 0 || nearest % 10 != 0)
            throw new ArgumentOutOfRangeException("nearest", "Must round to a positive multiple of 10");

        return (i + 5 * nearest / 10) / nearest * nearest;
    }
}